| First Author | Widmer U | Year | 1993 |
| Journal | J Immunol | Volume | 150 |
| Issue | 11 | Pages | 4996-5012 |
| PubMed ID | 8496601 | Mgi Jnum | J:12696 |
| Mgi Id | MGI:60930 | Doi | 10.4049/jimmunol.150.11.4996 |
| Citation | Widmer U, et al. (1993) Genomic cloning and promoter analysis of macrophage inflammatory protein (MIP)-2, MIP-1 alpha, and MIP-1 beta, members of the chemokine superfamily of proinflammatory cytokines. J Immunol 150(11):4996-5012 |
| abstractText | Macrophage inflammatory protein (MIP)-2, MIP-1 alpha, and MIP-1 beta all belong to the newly recognized chemokine superfamily of structurally related, activation-inducible cytokines with inflammatory and growth regulatory activities. We report the isolation and sequencing of genomic clones for murine MIP-2 and murine MIP-1 beta, and analyze their regulatory sequences in comparison with each other and with several other members of the chemokine family. The murine (mu)MIP-2 genomic clone displays the canonical four exon/three intron structure typical of other genes in the chemokine alpha subfamily (e.g., IL-8). Potential cis regulatory elements in the proximal promoter region were highly conserved between muMIP-2 and its three most closely related human homologs: human (hu)GRO-alpha, huGRO-beta, and huGRO-gamma. A mouse macrophage cell line, RAW 264.7, was transfected with a growth hormone reporter construct driven by a proximal fragment of the muMIP-2 5' promoter, and nested deletion mutant analysis localized the LPS responsive element to a region that contains a conserved NF kappa B consensus motif and lies 51 to 70 bp 5' from the transcription start site. In contrast to that of MIP-2, the muMIP-1 beta genomic clone exhibited the three exon/two intron structure characteristic of the chemokine beta family members (e.g., MCP-1). A comparison of the promoters for muMIP-1 beta and muMIP-1 alpha reveals a conserved CK-1 element, but transient expression studies in RAW 264.7 macrophages with proximal fragments of either the muMIP-1 beta or the muMIP-1 alpha 5' promoter fused to a human growth hormone reporter gene link LPS-inducibility in both to promoter segments near to, but not identical with, the consensus CK-1 sequence. Proximal 5' promoter fragments cloned from both the MIP-1 alpha and MIP-1 beta genes unexpectedly conferred constitutive expression on the fused reporter gene sequences in macrophage-like cells, but initial 5' deletion analysis did not link this responsiveness to known sequence motifs. The muMIP-1 beta promoter, but not the muMIP-1 alpha promoter, was constitutively active in B16 mouse melanoma cells, and both promoters were active in the myelomonocytic cell line WEHI 3B(A)d-, the muMIP-1 alpha promoter being three times stronger. |
